Carburetor



May 10, 1938. E. F. c. SEIGNOL ET Al.- 2,116,608

CARBURETOR Filed Nov. 16, 1933 3 Sheets-Sheet l ATTORNEYS.

May 10, 1938. E. F. c. SEIGNOL Er AL 2,116,608

CARBURETOR Filed Nov. 16, 1933 3 Sheets-Sheet 2 :FINE- E A TTORNEYS,

3 Sheets-Sheet 3 May l0, 1938. E. F. c. sElGNoL T AL A CARBURETOR FiledNov. 1e, 1955 A TT ORNEYS.

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Patented May 10, 1938 UNITED STATES PATENT "OFFICE GARBURETOR dustricsMecaniques S. A. D. I. M., Neuilly,

France, a corporation of France Application November 16, 1933, SerialNo. 698,252 In France November 21, 1932 8 Claims.

This invention h as for its object an improved carburetor having adifferential feed action and of the fuel lift type which draws fuel froma supply tank disposed at a lower level than the fuel nozzle of thecarburetor.

According to the invention the regulating of the air is insured throughthe combination of the following means:

(a) An air admission regulator located at the entrance of the diffuserof the carburetor, said regulator preferably operating automaticallyunder the action of the vacuum in the diffuser at every given moment;

(bi) An air entrance chamber in which works the regulator;

(c) A control device or throttle valve located either at the entrance orat the discharge end of the carburetor and simultaneously controllingthe positions of the regulator and the engine Speed.

The admission regulator comprises a tube the diameter of which issubstantially equal to the outlet of the carburetor and on which aresecured: on the one hand, a frusto-conical valve of such size that itmay close the convergent part of the diffuser of the carburetor, thesmall base of said truncated cone being preferably equal to the diameterof the neck of the diifuser multipled by and, on the other hand, a`piston sliding in a cylinder. In the case of an automatic regulation thepiston is controlled by variations of vacuum in the diffuser.

A dash-pot means is preferably provided so that the regulator may freelymove in its closing direction and is braked in its movements in itsopening direction. The air entrance may be so arranged that the airadmitted to the carburetor is directed under the large base of theregulating valve, so that the valve is braked in the sense of itsopening and, furthermore, that from the complete opening of the valvethe underside of this latter acts to reduce the entrance of the air.

The control device insuring the automatic Working of the regulatorisformed of a control valve which is located either at the delivery orat the entrance endof the carburetor.

The arrangement of the control valve at the delivery end of thecarburetor has the advantage, on the one hand, to avoid too great vacuumvalues on the free surface of the fuel which, in certain conditions oftemperature, may cause boiling phenomena and, on the other hand, torender the operation of the suction regulator independent of the staticvacuum variations in the admission pipe.

The entrance of the air into the carburetor is insured preferablythrough openings `provided along a circumference which is concentricwith the axis of the expansion chamber, the sum of the entering airquantities being substantially equal to the diameter of the delivery endof the carburetor. A circular ring valve provided with a control handleor member permits either the closing of said openings for insuring theoperating of the automatic starter hereunder described or for varyingthe section of said openings so as to act as a regulating valve.

The arrangement of the control valve at the entrance of the carburetorprovides advantages which, in certain cases, may be such that saidarrangement should be preferred, more particularly when the engine isnot submitted to sudden and frequent variations of its normal speed. Oneof said advantages is that the control valve, when it is located at theentrance, cannot be jammed by frost.

The entrance of the carburetor can also be formed, in the ordinarymanner, of an air admission pipe in which a regulating valve isarranged.

The fuel delivery is submitted to the action of a corrector or rather ofan economizer which acts on the vacuum producing the fuel delivery asthe opening of the throttle valve is diminished. Said corrector may bean automatic one, or may be manually actuated.

The special Carburation for starting is obtained by means of a starteroperated either manually or automatically, said starter having for itseect to diminish the vacuum acting on the free level of the fuel withoutacting on the vacuum on the nozzle.

The starter, when it is an automatic one, is regulated in such a mannerthat all the vacuum values at the level of the diifuser during theoperation of the carburetor cannot act on the same and that only Vacuumvalues which are notably greater are capable of acting on the saidstarter.

The illustrations of the appended drawings show, by way of example, a.lifting carburetor constructed according to the invention.

In the drawings:

Fig. 1 is a vertical section, on line I`-l of Fig. 2, through acarburetor embodying our invention.

Figs. 2, 3 and 4 are sectional plan views taken, respectively, on thelines 2 2, 3--3 and 4 4 of Fig. 1.

Fig. 5 is a diagrammatic View in section illustrating the fuel passagesshown in Figs. l to 4, inclusive.

Fig. 6 is a section on line 6--6 of Fig. 2.

Fig. 7 is a sectional view showing a modified form ofthe invention.

In order to facilitate the description similar members and pieces aredesignated by the same reference numerals.

In the embodiment according to Figs. 1 to 6, inclusive, the carburetorcomprises a constant level receptacle I supplied from a tank Ia, anozzle 2, a diffuser, 3, circularly arranged air inlets 4 and a throttlevalve 5. A rotary air entrance valve 54 having an operating handle ormember A54 is provided to regulate the inflow of air through inlets 4. Y

In the convergent part 3c of the diffuser is located the regulator I2comprising a valve having a lower conical surface I3, of an angleconforming to and which is parallel with the convergent part of thediffuser, and an upper conical surface or apex portion I4 of a greaterangle relative tothe convergent part of the diffuser than that of theconical part I3, the angle of the conical surface I4 being such as toprogressively increase or Vdiminish the size of the air admissionaperture formed between said surface I4 and the wall of part 3 of thediffuser as the valve in its working action moves downwardly or upwardlyto different degrees in the air chamber 23.

Said double cone is connected through a cylindrical ytube I5, thediameter of which is substantially equal to the diameter of the outletof the diffuser, with a driving piston I6 which can move against theaction of the spring I'I in a cylinder I8.

A tube 'I9 carried by the cone I4 connects through its opening 20 thedriving face of the Apiston I6 withthe expansion chamber formed by rthedivergent part 3by of the diffuser.

A dash-pot means formed of a calibrated air entrance 2| and a valve Y22brakes the movements of the piston I6 downwards and leaves said'pistonfree 'in its upward movement.

The circular openings 4 form the air entrance proper of the carburetor.The constant level lreceptacle I is `closed and connected with the `neck3a of the diffuser: on the one hand, at its lower part, through theconduit 6, the fuel nozzle 2, the chamber 'I and the slot 8 in the neck3a of the diffuser, and on the other hand, in its upper part, above thefree level of the fuel, through the conduit 9, the annular chamber I andone or more holes II with the divergent part ,3b ofthe diffuser.

.As the vacuum in the neck 3a of the diffuser is always greater than thevacuum before the opening or openings II, the fuel is drawn by theAaction of Athe engine into the diffuser through the nozzle 2, but thedelivery of the same is constantly braked by `the vacuum transmittedthrough the conduit 9 above the free level of the fuel, said vacuumvarying between two values, the one a maximum value and the other aminimum value, in a direct ratio with the opening of the regulator I2.

Said vacuum values, which are always maintained at a high rate by theconstruction of the regulator, are sucient if the carburetor is notsupplied with fuel from above, for drawing in,

.in all cases up to the constant level receptacle,

the fuel'from a container located therebelow.

The operation of the carburetor is as follows:

When the throttle valve is opened the suction exerted in the divergentpart 3b of the diffuser on the end of the tube I9 opening into the sameis transmitted to the driving face of the piston I6 and opens regulatorI2 in such a manner that it automatically takes a position'corresponding to the opening of the regulating valve 5.

The wider the valve 5 is opened, the greater the amount of air permittedto enter the diffuser.

The feed delivery of fuel from the nozzle 2 to the chamber 'I of thediffuser is governed by the action of an automatic differentialcorrector and economizer shown in Fig. 6. The construction and operationof this corrector and economizer is as follows:

A calibrated air entrance in the form of a nipple 44 communicatesthrough a port 45 with a channel or conduit 46 connected with thechamber 'I and through a port 4'I with the chamber I6. Another channelor conduit 48 communicates at one end with chamber I@ and passage 46directly or through port 4'I and communicates at its opposite end withthe mixture passage posteriorly of the valve 5, said channel 43providing a by-pass about valve 5. Conduits 46 and 48 serve as idlingmixture feed passages for idling speeds, and passage 46 also acts toconvey gases from I I, III to 'I, 8 for a circulatory mixing actionduring such times as there exists certain differences in pressurebetween II and 8, as hereinafter described. The nipple 44 supplies airto form the idling mixture for idling speeds and at high speeds it actsas an economizer by venting the chamber 'I and thereby reducing thesuction on the fuel supply. It will be understood that at lowest idlingspeed with valve 5 in closed or almost completely closed positionpassage 48 serves to maintain a desired vacuum in the diffuser 3 andpassage S and to allow feed of fuel to the engine. In such position ofthe valve 5 the vacuum values between 'I and I6 are very vnear oneanother and air for the idling fuel feed is supplied through nipple 44for the production of the no-load emulsion or mixture in the chamber 'Iand conduit 46. This mixture is drawn into the engine through conduits46 and 48, but in case any of the mixture enters the venturi throughslot 8 it will also be drawn through openings II and chamber I6 forpassage through conduit 48 to the engine. At higher idling speeds orintermediate speeds, with valves 5 and I2 open to small degrees, throughthe change of vacuum differential occurring between .IO and 'I there isa tendency for the production of a circulatory current of a portion ofthe gaseous mixture from the divergent part of the venturi downwardthrough openings II and chamber I6 to chamber 'I and thence ythroughslot 8 back into the venturi for upward travel therein. The volume andvelocity of this current tend to increase in proportion to the degree ofopening movement of valve IZ, but such Acurrent is checked andcontrolled against its volume and velocity becoming excessive at allidling and intermediate speeds by the relief action due to the inducedgreater flow of air at such times through the nipple 44. Thiscirculatory current so produced is not detrimental to a proper feedaction but on the contrary results, through the increased agitationwhich it causes, in the formation of a better mixture for use at suchspeeds and an economizing action at intermediate speeds by venting thechamber 'I and reducing the suction on the fuel supply.

At the end of the conduit 9 is an automatic starting device formed of ahollow valve needle 55 resting upon the seat 56 against which it ispressed by a spring l. The openings 58 permit the atmospheric air toenter the conduit 9 when the valve needle 55 has been lifted from itsseat.

'I'he operation of the automatic starter is as follows:

When the air entrance ring or choke valve 54 is closed the total vacuumof vthe suction pipe establishes itself `in the diffuser 3, the openingsIl, the chamber l0 and the conduit 9. Under the action of this greatvacuum the valve needle 55 is drawn in, compressing the spring 51 anduncovering the openings 58, thus permitting the atmospheric air to`enter the conduit 9, which has for its effect to diminish the vacuum inthe upper part of the constant level receptacle and therefore, toincrease the quantity of fuel entering the diffuser.

In the embodiment according to Fig. 'l the air chamber 23 freelycommunicates with the atmosphere through the holes 4 which arecircularly arranged around the axis of the chamber 23 and in such anumber that their total section is at least equal to the section of thediffuser. In the air chamber 23 is disposed a nozzle ID3 the section ofwhich is approximately the same as the section of the diffuser of thecarburetor and which collects the air in a rising current in line withthe valve I2. The air flows into the chamber 23 before reaching thediffuser. The rising air current brakes or checks the movement of thevalve l2 in the direction downwards and tends to push it to the closedposition, the air pressure in this case thus acting in the manner as thespring Il in Fig. 1.

By arranging the nozzle |03 in such a manner that from the completeopening of the diffuser the lower base of the valve I2 reduces the airsupply in a predetermined measure, the quantity of air which is admittedwill never eX- ceed a predetermined fixed value.

What we claim is:

1. In a carburetor elevating fuel from a lower reservoir and having anair entrance, a diffuser having a constricted portion, a divergingportion posterior to said constricted portion and leading therefrom anda converging portion anterior to said constricted portion and disposedbetween the same and the air entrance, a closed constant levelreceptacle, a conduit leading from the bottom of the said receptacle tothe constricted portion of the diffuser of the carburetor through anozzle of predetermined section opening in a chamber surrounding theconstricted portion of the said diffuser and communicating therewith, anair entrance to the carburetor a conduit leading from the upper part ofthe said constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrustoconical regulating valve located in the converging portion of thediffuser and longitudinally movable therein and adapted tofvary thecross section of the said converging portion and the supply of airadmitted thereto from the air entrance, a tube connected to the saidregulating valve and opening at one end into the diverging portion ofthe said diffuser at a point posterior to the constricted portion of thediffuser, a piston connected to the other end of said tube, a closedcylinder in which slides the piston and which communicates with thediverging portion of the diffuser through said tube, means acting toconstantly push the regulating Valve towards the closing position of thesame, a conduit leading fromthe diverging portion of the diffuser to thechamber surrounding the constricted portion of the diffuser, arestricted air feed connection between the `atmosphere and the saidconduit and chamber surroundingthe constricted portion of the diffuserfor supplying air thereto, and a starting valve for establishingcommunication between the atmosphere and the upper part of the constantlevel receptacle and opening in the direction of said receptacle.

2. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating valve located in the converging portion ofthediffuser and longitudinally movable therein and adapted to vary thecross sectionof the said converging portion, a tube connected to thesaid regulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said tube, a closed cylinder in whichslides the piston .and which communicates with the diverging portion ofthe diffuser through the tube, an air entrance to the carburetor, meansacting to constantly push the regulating valve towards the closingposition of the same, a valve located at the air entrance of thecarburetor and varying the cross section of the said entrance from zeroto its maximum, a conduit leading from the diverging portion of thediffuser to the chamber surrounding the constricted portion of thediffuser, a restricted air feed inlet communicating with said conduitand chamber, and a starting valve interposed between the atmosphere andthe upper part of the constant level receptacle and opening in thedirection of said receptacle.

3. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle tol the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating `valve located Ain the converging portion ofthe diffuser and longitudinally movable therein and adapted to vary thecross section of the said converging portion, a tube connected to thesaid regulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said tube, a closed cylinder in whichslides the piston and which communicates with the diverging portion ofthe diffuser through the tube, means acting to constantly push theregulating valve towards the closing position of the same, a conduitleading from the diverging portion of the diffuser to the chambersurrounding the constrictedportion of the diiuser, an` always openrestricted air feed connection between the atmosphere and said conduitand chamber, a starting valve interposed between the atmosphere and theupper part of the constant level receptacle and opening in the directionof said receptacle, and a manually operable control throttle valvelocated posterior to the diffuser to vary from a small value to itsmaximum the section of the conduit leading from the dii'user to theengine fed by the carburetor.

4. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating valve lo.- cated in the converging portion o-fthe diiuser and longitudinally movable therein and adapted to vary thecross section of the said converging portion, a tube connected to thesaid regulating Valve and opening in the diverging portion of the saiddiuser at a point posterior to the constricted portion of the diffuser,a piston connected to said tube, a closed cylinder in which slides thepiston and which communicates with the diverging portion of the diffuserthrough the tube, means acting to constantly push the regulating valvetowards the closing position of the same, a conduit leading from thediverging portion of the diffuser to the chamber surrounding theconstricted portion of the diffuser, a nipple having a restricted airpassage leading from the atmosphere for supplying air to the chambersurrounding the constricted portion of the diffuser, and a startingvalve interposed between the atmosphere and the upper part of theconstant level receptacle and opening in the direction of saidreceptacle.

5. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saidldiffuser ata point posterior tol the constricted portion of the same, afrusto-conical regulating valve located in the converging portion of thediffuser and longitudinally movable therein and adapted to vary thecross section of the said converging part, a tube connected to the saidregulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said' tube, a closed. cylinder in whichslides the piston and which communicates with the diverging portion ofthe diffuser through the tube, an air intake entrance to the carburetormeans acting to constantly push the regulating valve towards the closingposition of the same, a means at the air entrance of the carburetor forvarying the cross section of the said entrance from zero to its maximum,a conduit leading from the diverging portion of the diffuser to thechamber surrounding the constricted portion of the diffuser, an airsupply connection between the atmosphere and said conduit and thechamber surrounding the co-nstricted portion of the diffuser, a startingvalve interposed between the atmosphere and the upper part of theconstant level receptacle and opening in the direction of saidreceptacle, a spring holding the said valve in its closing position andthe value of the strength of which is such that it allows the startingvalve to open when the vacuum in the constant level receptacle issubstantially higher than the normal vacuum therein corresponding to thenormal operation of the carburetor, due to the closing of the airentrance of the carburetor for starting the engine fed by thecarburetor, and a control throttle valve located posterior to thediffuser to vary from a small value to its maximum the section of theconduit leading from the diffuser to the engine fed by the carburetor.

6. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper portion of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating valve located in the converging portion of thediffuser and longitudinally movable therein and adapted to vary thecross section of the said converging portion, a tube connected to'thesaid regulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said tube, a closed cylinder in whichslides the piston and which communicates with the diverging portion ofthe diffuser through the tube, means acting to constantly push theregulating valve towards the closing position of the same, an airentrance to the carburetor, a hand operated valve located at the airentrance of the carburetor for varying the cross section of the saidentrance from zero to its maximum, a conduit leading from the divergingportion of the diffuser to the chamber surrounding the constrictedportion of the diffuser, a restricted air feed connection between theatmosphere and said conduit and chamber surrounding the constrictedportion of the diiuser for supplying air thereto, a starting valveinterposed between the atmosphere and the upper part of the constantlevel receptacle and opening in the direction of said receptacle and aspring holding the said valve in its closing position and the Value ofthe strength of which is such that it allows the starting valve to openwhen the vacuum in the constant level receptacle, is substantiallyhigher than the normal vacuum therein corresponding to the normaloperation of the care buretor, due to the closing of the air entrance ofthe carburetor for increasing at will and incidentally the pressure inthe constant level receptacle.

7. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating valve located in the converging portion of thediffuser and longitudinally movable therein and adapted to vary thecross section of the said converging portion, a tube connected to thesaid regulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said tube, a closed cylinder in whichslides the piston and which communicates with the diverging portion ofthe diffuser through the tube, a dash-pot means cooperating with thepiston and cylinder for exerting a braking action on the openingmovement of the regulating valve, means acting to constantly push theregulating valve towards the closing position of the same, an airentrance to the carburetor, a valve located at the air entrance of thecarburetor for varying the cross section of the said entrance from zeroto its maximum, a conduit leading from the diverging portion of thediffuser to the chamber surrounding the constricted portion of thediffuser, a restricted air feed connection between the atmosphere andsaid conduit and the chamber surrounding the constricted portion of thediffuser for supplying air thereto, and a starting valve interposedbetween the atmosphere and the upper part of the constant levelreceptacle and opening in the direction of said receptacle.

8. In a carburetor elevating fuel from a lower reservoir to a closedconstant level receptacle, a conduit leading from the bottom of the saidreceptacle to the constricted portion of the diffuser of the carburetorthrough a nozzle of predetermined section opening in a chambersurrounding the constricted portion of the said diffuser andcommunicating therewith, a conduit leading from the upper part of thesaid constant level receptacle to the diverging portion of the saiddiffuser at a point posterior to the constricted portion of the same, afrusto-conical regulating valve located in the converging portion of thediffuser and longitudinally movable therein and adapted to vary thecross section of the said converging portion, a tube connected to thesaid regulating valve and opening in the diverging portion of the saiddiffuser at a point posterior to the constricted portion of thediffuser, a piston connected to said tube, a closed cylinder in whichslides the piston and which communicates with the diverging portion ofthe diffuser through the tube, means acting to constantly push theregulating valve towards the closing position of the same, a conduitleading from the divergingl portion of the diffuser to the chambersurrounding the constricted portion of the diffuser, a restricted airfeed connection between the atmosphere and the said conduit and saidchamber surrounding the constricted portion of the diffuser forsupplying air thereto, a starting valve interposed between theatmosphere and the upper part of the constant level receptacle andopening in the direction of said receptacle, means cooperating with saidvalve to open the same for starting the engine fed by the carburetor, anair entrance to the carburetor, an air chamber interposed between theair entrance of the carburetor and the air entrance ofthe convergingportion of the diffuser, and an air conduit surrounding the regulatingvalve carrying tube and of a section not larger than the greater base ofthe said regulating valve, the distance between said conduit and theregulating valve when in its closing position being such that the flowof air penetrating in the air chamber brakes the opening movement of theregulating valve and automatically limits to a predetermined extent theow of air entering the carburetor.

EDOUARD FREDERIC CHARLES SEIGNOL. FRANCIS JULES MONIER.

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